Commit-ID: 2b54ab3c66d48a5887c9ba209a342d0b13cdefa8
Gitweb: http://git.kernel.org/tip/2b54ab3c66d48a5887c9ba209a342d0b13cdefa8
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Mon, 8 Feb 2016 08:47:48 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 8 Feb 2016 09:11:53 +0100
x86/mm/numa: Fix memory corruption on 32-bit NUMA kernels
The following commit:
a0acda917284 ("acpi, numa, mem_hotplug: mark all nodes the kernel resides un-hotpluggable")
Introduced numa_clear_kernel_node_hotplug(), which function is executed
during early bootup, and which marks all currently reserved memblock
regions as hot-memory-unswappable as well.
y14sg1 <y14sg1@xxxxxxxxxxx> reported that when running 32-bit NUMA kernels,
the grsecurity/PAX kernel patch flagged a size overflow in this function:
PAX: size overflow detected in function x86_numa_init arch/x86/mm/numa.c:691 [...]
... the reason for the overflow is that memblock_set_node() takes physical
addresses as arguments, while the start/end variables used by
numa_clear_kernel_node_hotplug() are 'unsigned long', which is 32-bit on PAE
kernels, but which has 64-bit physical addresses. So we truncate a 64-bit
physical range to 32 bits and pass it to memblock_set_node(), which corrupts
memory on systems with physical addresses above 4GB.
The fix is to use the proper type to handle physical addresses, phys_addr_t.
Reported-by: y14sg1 <y14sg1@xxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Brad Spengler <spender@xxxxxxxxxxxxxx>
Cc: Chen Tang <imtangchen@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: PaX Team <pageexec@xxxxxxxxxxx>
Cc: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Wen Congyang <wency@xxxxxxxxxxxxxx>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/mm/numa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index c3b3f65..d04f809 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -469,7 +469,7 @@ static void __init numa_clear_kernel_node_hotplug(void)
{
int i, nid;
nodemask_t numa_kernel_nodes = NODE_MASK_NONE;
- unsigned long start, end;
+ phys_addr_t start, end;
struct memblock_region *r;
/*
--
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